JPH0621975Y2 - Pin fixing device for construction machinery - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] This invention is intended to rotatably attach an end attachment such as an excavator for excavation, a backhoe or a bucket to a support such as an arm in a construction machine such as a hydraulic excavator. The present invention relates to a pin fixing device in a pin connecting portion of the above.

[Prior Art] In a construction machine such as a hydraulic excavator, an excavator for excavation, a backhoe, a bucket, or other end attachment is rotatably connected to a support such as an arm by a pin according to a work purpose. There is.

This mounting pin must be fixed to the attachment, and the fixing means is as shown in FIG.
Attachment hole 2 and attachment 3 for support 1 such as an arm
It is general that a diametrical insertion hole 6 is provided at an end of a mounting pin 5 penetrating the mounting hole 4 and is fixed to a collar 7 welded and fixed to a side surface of the attachment 3 with a bolt and a double nut. .

Further, as shown in FIG. 8, a lock pin 11 is used in place of the bolt and nut, a groove is provided on the outer periphery of the collar 7, and both ends of the lock pin are covered by a stopper ring 13 'fitted in the groove. It is also proposed to hold and fix. (See Japanese Utility Model Publication No. 56-29421) As yet another proposal, as shown in FIG. 9, there is known one in which the lock pin 11 is fixed by a rubber expandable endless ring 13 ″. 63-
[Problem to be solved by the present invention] However, the one shown in FIG. 7 not only has a risk of damaging bolt heads, nuts and the like due to earth and sand at the time of working and loosening of nuts, but also for mounting. A tool such as a wrench is required when replacing the pin 5, and the lock pin 11 may drop out when the elastic force of the stopper ring 13 'is reduced in the structure shown in FIG. At the time of replacement, there is a problem that it is necessary to remove the stopper ring 13 'from the groove on the outer periphery of the collar 7 using a tool.

Further, the rubber endless ring as shown in FIG. 9 does not require a work tool when it is attached, but when it is detached, it is made of rubber that is fitted in the annular groove on the outer circumference of the collar. It is necessary to pull the endless ring 13 ″ out of the groove by some means and not only needs a working tool for that, but also to strongly pull and pull a part of the rubber endless ring to damage it. In addition, it is easy to be damaged by earth and sand at the time of work, and as a characteristic of rubber, the life is short because the growth is quick even with a small scratch due to small damage,
There is a problem that it cannot be used as an attachment for attachments such as excavators.

As described above, according to the conventionally known fixing means, fixing tools such as bolts, nuts and stopper rings need to be temporarily removed from the collar when the mounting pins are replaced, and therefore a working tool such as a spanner is required. However, there is a problem that these fixtures are easily dropped and lost on the ground, and a solution to this problem remains another problem that they are easily damaged by earth and sand and have a short life.

The present invention is intended to solve the above-mentioned problems, does not require a working tool when mounting the mounting pin, and further, does not require removal of the lock pin fixing tool, and is intended for long-term use. It seeks to provide a secure means of withstanding.

[Means for Solving the Problem] The present invention provides a means for solving the above-mentioned problems, and the attachment pin 5 rotatably connects the attachment 3 to the support 1. In the attachment coupling device for a construction machine, a collar 7 having an insertion hole 8 through which one end of the attachment pin 5 can be inserted is provided on a side surface of the attachment 3, and a concave groove 10 is formed on the outer periphery of the collar 7.
And the pin 5 and the collar 7 are provided with diametrical through holes 6 and 9, and a spring steel elastic ring 13 is rotatably inserted into the through holes 6 and 9. 1
1 through which the elastic ring 13 is bent at both ends.
has an overlap portion 13a which forms a b, the inner diameter d ₂ is normally is a smaller diameter than the groove diameter d ₁ of the groove 10, enables expansion in the range of length l of the overlapping portion A pin fixing device for a pin connecting portion of a construction machine is characterized in that the pin fixing device can be fitted into and removed from the concave groove 10 on the outer periphery of the collar.

[Embodiment] In the drawings, reference numeral 1 denotes a support portion at the tip of an arm of a hydraulic excavator, which is provided with an insertion hole 2 for an attachment attachment connecting pin 5. Reference numeral 3 denotes a bracket portion of an attachment such as a bucket, which also has an insertion hole 4. A through hole 6 for inserting the lock pin 11 in the diametrical direction is formed at one end of the connecting pin 5.

Reference numeral 7 denotes a collar projecting from a side surface of the bracket of the attachment 3, which has an insertion hole 8 through which one end of the connecting pin 5 can be inserted at a central portion thereof, and a through hole which communicates with the through hole 6 in a diameter direction. A hole 9 is formed, and a groove 10 is formed on the outer circumference over the entire circumference.

A lock pin 11 is inserted into the through holes 6 and 9, and an elastic ring 13 made of spring steel is rotatably inserted through the insertion hole 12.

The elastic ring 13 is made of spring steel made by bending a thin steel bar into an annular shape and has an overlap portion 13a, and the inner diameter d ₂ thereof is smaller than the groove diameter d _{1 of the} concave groove 10. , Can be expanded within the range of the length l of the overlapping portion 13a and can be freely inserted into and removed from the concave groove 10. Bent portions 13b are formed at both ends of the overlapping portion 13a, and the folded portions 13b serve as a stopper for retaining and serve as a grip portion at the time of expansion.

[Operation] The present invention has the above-described configuration, and when fixing the attachment 3 such as a bucket and the connecting pin 5, the connecting pin 5 and the through holes 6 and 9 of the collar 7 are aligned with each other to lock the pin 11. After inserting, the elastic ring 13 may be expanded and rotated around the insertion portion 12 so as to fit into the groove 10 on the outer periphery of the collar.

When the attachment 3 and the connecting pin 5 are unlocked, the bent portion 13b is gripped from the state shown in the figure and the overlap portion 13a of the elastic ring 13 is pushed open to expand the elastic ring 13 to form the concave groove 10. After the engagement is released, the insertion part 12
The lock pin 11 may be pulled out by rotating it around.

[Effect] According to the present invention, the spring steel elastic ring 13 is rotatably attached to the lock pin 11, and the elastic ring 13 can be inserted into and removed from the concave groove 10 on the outer periphery of the collar. At the time of attaching and detaching the pin, it suffices to hold the bent portions 13b at both ends of the elastic ring 13 and to widen the overlap portion 13a, no working tool is required, and the elastic ring 13 is always provided with the lock pin 11a. Since the lock pin 11 is inserted in the lock pin 11 and is prevented from coming off by the bent portion 13b, there is no fear of loss when the lock pin 11 is pulled out, and the lock pin 11 is made of spring steel and fits into the groove 10 when mounted. There is no risk of damage even if it comes into contact with soil during work, and it has the effect of withstanding long-term use.

[Brief description of drawings]

1 to 6 show an embodiment of the present invention, FIG. 1 is a vertical sectional front view, FIG. 2 is an explanatory view of a collar, FIG. 3 is an external view of a lock pin, and FIG. 4 is an elastic ring. Explanatory drawing, FIG. 5 and FIG. 6 are perspective views showing a state in which the elastic ring is attached to the lock pin. FIG. 7, FIG. 8 and FIG. 9 are explanatory views showing a conventional example. 1: Support 2: Mounting pin insertion hole 3: Attachment 4: Mounting pin insertion hole 5: Mounting pin 6: Through hole 7: Collar 8: Insertion hole 9: Through hole 10: Recessed groove 11: Lock Pin 12: Insertion hole (for elastic ring) 13: Elastic ring

Claims (1)

[Scope of utility model registration request] 1. An attachment connecting device for a construction machine, wherein an attachment (3) is rotatably connected to a support (1) by a connecting pin (5).
Insertion hole (8) through which one end of the connecting pin (5) can be inserted on the side surface of the
A collar (7) provided with is projected, and a concave groove is formed on the outer periphery of the collar (7).
(10) is recessed, and diametrical through holes (6) and (9) are formed in the pin (5) and the collar (7), and the through holes (6) and (9) are formed.
A spring steel elastic ring (13) is rotatably inserted through a lock pin (11), and the elastic ring (13) has an overlapping portion (b) formed with bent portions (13b) at both ends. 13a), the inner diameter (d ₂ ) of which is normally smaller than the groove diameter (d ₁ ) of the concave groove (10), but is expanded within the range of the length (l) of the overlapping portion. A pin fixing device for a pin connecting portion of a construction machine, which can be opened and can be freely inserted into and removed from the concave groove (10) on the outer periphery of the collar.